Struct lang hooks
このページを編集する際は，編集に関する方針に従ってください． 概要 *gcc-4.1.0/gcc/langhooks.hにて定義 * hook とは，特定の場面で呼び出される関数 (へのポインタ) を格納した変数のこと． lhd_* は，langhooks-def.h のプリフィックス． そこで定義された関数 lhd_foo へのポインタを格納する構造体． 実装 203 /* Language-specific hooks. See langhooks-def.h for defaults. */ 204 205 struct lang_hooks 206 { 207 /* String identifying the front end. e.g. "GNU C++". */ 208 const char *name; 209 210 /* sizeof (struct lang_identifier), so make_node () creates 211 identifier nodes long enough for the language-specific slots. */ 212 size_t identifier_size; 213 214 /* Determines the size of any language-specific tcc_constant or 215 tcc_exceptional nodes. Since it is called from make_node, the 216 only information available is the tree code. Expected to die 217 on unrecognized codes. */ 218 size_t (*tree_size) (enum tree_code); 219 220 /* The first callback made to the front end, for simple 221 initialization needed before any calls to handle_option. Return 222 the language mask to filter the switch array with. */ 223 unsigned int (*init_options) (unsigned int argc, const char **argv); 224 225 /* Callback used to perform language-specific initialization for the 226 global diagnostic context structure. */ 227 void (*initialize_diagnostics) (struct diagnostic_context *); 228 229 /* Handle the switch CODE, which has real type enum opt_code from 230 options.h. If the switch takes an argument, it is passed in ARG 231 which points to permanent storage. The handler is responsible for 232 checking whether ARG is NULL, which indicates that no argument 233 was in fact supplied. For -f and -W switches, VALUE is 1 or 0 234 for the positive and negative forms respectively. 235 236 Return 1 if the switch is valid, 0 if invalid, and -1 if it's 237 valid and should not be treated as language-independent too. */ 238 int (*handle_option) (size_t code, const char *arg, int value); 239 240 /* Return false to use the default complaint about a missing 241 argument, otherwise output a complaint and return true. */ 242 bool (*missing_argument) (const char *opt, size_t code); 243 244 /* Called when all command line options have been parsed to allow 245 further processing and initialization 246 247 Should return true to indicate that a compiler back-end is 248 not required, such as with the -E option. 249 250 If errorcount is nonzero after this call the compiler exits 251 immediately and the finish hook is not called. */ 252 bool (*post_options) (const char **); 253 * 言語固有の初期化を行う lang_dependent_init 関数から呼ばれる． 254 /* Called after post_options to initialize the front end. Return 255 false to indicate that no further compilation be performed, in 256 which case the finish hook is called immediately. */ 257 bool (*init) (void); 258 259 /* Called at the end of compilation, as a finalizer. */ 260 void (*finish) (void); 261 * compile_file 関数で呼び出される．非ゼロの時デバッグ情報を出力． 262 /* Parses the entire file. The argument is nonzero to cause bison 263 parsers to dump debugging information during parsing. */ 264 void (*parse_file) (int); 265 * compile_file 関数で呼び出される． 266 /* Called immediately after parsing to clear the binding stack. */ 267 void (*clear_binding_stack) (void); 268 269 /* Called to obtain the alias set to be used for an expression or type. 270 Returns -1 if the language does nothing special for it. */ 271 HOST_WIDE_INT (*get_alias_set) (tree); 272 273 /* Called with an expression that is to be processed as a constant. 274 Returns either the same expression or a language-independent 275 constant equivalent to its input. */ 276 tree (*expand_constant) (tree); 277 278 /* Called by expand_expr for language-specific tree codes. 279 Fourth argument is actually an enum expand_modifier. */ 280 rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *); 281 282 /* Called by expand_expr to generate the definition of a decl. Returns 283 1 if handled, 0 otherwise. */ 284 int (*expand_decl) (tree); 285 286 /* Hook called by safe_from_p for language-specific tree codes. It is 287 up to the language front-end to install a hook if it has any such 288 codes that safe_from_p needs to know about. Since same_from_p will 289 recursively explore the TREE_OPERANDs of an expression, this hook 290 should not reexamine those pieces. This routine may recursively 291 call safe_from_p; it should always pass `0' as the TOP_P 292 parameter. */ 293 int (*safe_from_p) (rtx, tree); 294 295 /* Function to finish handling an incomplete decl at the end of 296 compilation. Default hook is does nothing. */ 297 void (*finish_incomplete_decl) (tree); 298 299 /* Mark EXP saying that we need to be able to take the address of 300 it; it should not be allocated in a register. Return true if 301 successful. */ 302 bool (*mark_addressable) (tree); 303 304 /* Hook called by staticp for language-specific tree codes. */ 305 tree (*staticp) (tree); 306 307 /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the 308 DECL_NODE with a newly GC-allocated copy. */ 309 void (*dup_lang_specific_decl) (tree); 310 311 /* Set the DECL_ASSEMBLER_NAME for a node. If it is the sort of 312 thing that the assembler should talk about, set 313 DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE. 314 Otherwise, set it to the ERROR_MARK_NODE to ensure that the 315 assembler does not talk about it. */ 316 void (*set_decl_assembler_name) (tree); 317 318 /* Return nonzero if fold-const is free to use bit-field 319 optimizations, for instance in fold_truthop(). */ 320 bool (*can_use_bit_fields_p) (void); 321 322 /* Nonzero if operations on types narrower than their mode should 323 have their results reduced to the precision of the type. */ 324 bool reduce_bit_field_operations; 325 326 /* Nonzero if this front end does not generate a dummy BLOCK between 327 the outermost scope of the function and the FUNCTION_DECL. See 328 is_body_block in stmt.c, and its callers. */ 329 bool no_body_blocks; 330 331 /* The front end can add its own statistics to -fmem-report with 332 this hook. It should output to stderr. */ 333 void (*print_statistics) (void); 334 335 /* Called by print_tree when there is a tree of class tcc_exceptional 336 that it doesn't know how to display. */ 337 lang_print_tree_hook print_xnode; 338 339 /* Called to print language-dependent parts of tcc_decl, tcc_type, 340 and IDENTIFIER_NODE nodes. */ 341 lang_print_tree_hook print_decl; 342 lang_print_tree_hook print_type; 343 lang_print_tree_hook print_identifier; 344 345 /* Computes the name to use to print a declaration. DECL is the 346 non-NULL declaration in question. VERBOSITY determines what 347 information will be printed: 0: DECL_NAME, demangled as 348 necessary. 1: and scope information. 2: and any other 349 information that might be interesting, such as function parameter 350 types in C++. */ 351 const char *(*decl_printable_name) (tree decl, int verbosity); 352 353 /* This compares two types for equivalence ("compatible" in C-based languages). 354 This routine should only return 1 if it is sure. It should not be used 355 in contexts where erroneously returning 0 causes problems. */ 356 int (*types_compatible_p) (tree x, tree y); 357 358 /* Given a CALL_EXPR, return a function decl that is its target. */ 359 tree (*lang_get_callee_fndecl) (tree); 360 361 /* Called by report_error_function to print out function name. */ 362 void (*print_error_function) (struct diagnostic_context *, const char *); 363 364 /* Called from expr_size to calculate the size of the value of an 365 expression in a language-dependent way. Returns a tree for the size 366 in bytes. A frontend can call lhd_expr_size to get the default 367 semantics in cases that it doesn't want to handle specially. */ 368 tree (*expr_size) (tree); 369 370 /* Convert a character from the host's to the target's character 371 set. The character should be in what C calls the "basic source 372 character set" (roughly, the set of characters defined by plain 373 old ASCII). The default is to return the character unchanged, 374 which is correct in most circumstances. Note that both argument 375 and result should be sign-extended under -fsigned-char, 376 zero-extended under -fno-signed-char. */ 377 HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT); 378 379 /* Pointers to machine-independent attribute tables, for front ends 380 using attribs.c. If one is NULL, it is ignored. Respectively, a 381 table of attributes specific to the language, a table of 382 attributes common to two or more languages (to allow easy 383 sharing), and a table of attributes for checking formats. */ 384 const struct attribute_spec *attribute_table; 385 const struct attribute_spec *common_attribute_table; 386 const struct attribute_spec *format_attribute_table; 387 388 /* Function-related language hooks. */ 389 struct lang_hooks_for_functions function; 390 391 struct lang_hooks_for_tree_inlining tree_inlining; 392 393 struct lang_hooks_for_callgraph callgraph; 394 395 struct lang_hooks_for_tree_dump tree_dump; 396 * compile_file 関数で呼び出される． 397 struct lang_hooks_for_decls decls; 398 399 struct lang_hooks_for_types types; 400 401 /* Perform language-specific gimplification on the argument. Returns an 402 enum gimplify_status, though we can't see that type here. */ 403 int (*gimplify_expr) (tree *, tree *, tree *); 404 405 /* Fold an OBJ_TYPE_REF expression to the address of a function. 406 KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT. */ 407 tree (*fold_obj_type_ref) (tree, tree); 408 409 /* Return a definition for a builtin function named NAME and whose data type 410 is TYPE. TYPE should be a function type with argument types. 411 FUNCTION_CODE tells later passes how to compile calls to this function. 412 See tree.h for its possible values. 413 414 If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME, 415 the name to be called if we can't opencode the function. If 416 ATTRS is nonzero, use that for the function's attribute list. */ 417 tree (*builtin_function) (const char *name, tree type, int function_code, 418 enum built_in_class bt_class, 419 const char *library_name, tree attrs); 420 421 /* Used to set up the tree_contains_structure array for a frontend. */ 422 void (*init_ts) (void); 423 *recompute_tree_invarant_for_addr_expr関数から呼ばれる 424 /* Called by recompute_tree_invarant_for_addr_expr to go from EXPR 425 to a contained expression or DECL, possibly updating *TC, *TI or 426 *SE if in the process TREE_CONSTANT, TREE_INVARIANT or 427 TREE_SIDE_EFFECTS need updating. */ 428 tree (*expr_to_decl) (tree expr, bool *tc, bool *ti, bool *se); 429 430 /* Whenever you add entries here, make sure you adjust langhooks-def.h 431 and langhooks.c accordingly. */ 432 };